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EST Calendar 2020 Solar regions active Top: Jules Janssen (1885). Bottom: Hinode’s Broadband Filter Imager (2009) Photograph of an active region, taken by Jules Janssen on 22 June 1885 at the Observatoire de Meudon (Paris, France). In addition to the sun- spots and pores of the active region, the granulation pattern of the solar surface can clearly be seen. The photograph recorded a very large feld of view, and parts of it appear blurred because of the efects of atmospheric January 4: turbulence. Peak of Quadrantids meteor shower (08:20 GMT) The lower panel shows active region 11029 as observed by the Hinode sa- January 13-15: nd tellite on 27 October 2009 near the edge of the solar disk. The image quality 2 NCSP DKIST Data Training Workshop, is homogeneous over the entire feld of view because the measurements are California State University, Northridge, USA not afected by the Earth atmosphere. As usual, one of the spots forming the January 21: active region is larger and more stable than the other, which appears frag- EAST General Assembly, Prague, Czech Republic mented into many small pores. JANUARY MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 30 31 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Solar granulation Top: Jules Janssen (1890). Bottom: Swedish 1m Solar Telescope (2004) The image at the top is a particularly good example of early photo- graphs of the solar granulation. It was taken by Jules Janssen at the Obser- vatoire de Meudon (France) on 11 October 1890, from a projection of the solar disk measuring 1.2 meters in diameter. The photograph captured the granulation pattern of the solar surface with surprising detail. However, the February 3-7: feld of view is so large that parts of the image appear blurred by turbulence 5th Asia Pacifc Solar Physics Meeting, Pune, India in the Earth’s atmosphere. February 5: The CCD image at the bottom shows the solar granulation as seen by the Swe- Solar Orbiter Launch, Cape Canaveral, USA dish 1-m Solar Telescope on La Palma (Spain) on 22 August 2004. The obser- February 11: vations were acquired using adaptive optics and subsequently reconstructed International Day of Women and Girls in Science with sophisticated techniques to reach the difraction limit of the telescope. In addition to granules and intergranular lanes, one can observe tiny bright points that represent small-scale magnetic felds on the solar surface. FEBRUARY MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 30 31 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Solar flares Top: Richard C. Carrington (1859). Bottom: Hinode’s Broadband Filter Imager (2007) Original drawing of the frst detection of a solar fare (top). “I had secured diagrams of all the groups and detached spots, […] when two patches of intensely bright and white light broke out, in the positions indicated in the ap- pended diagram by the letters A and B, and of the forms of the spaces left white. My frst impression was that by some chance a ray of light had penetrated a hole March 20: in the screen [...], for the brilliancy was fully equal to that of direct sun-light.” Spring Equinox (03:50 GMT) Carrington, MNRAS, 20, 13 (1859). March 23-27: st The image at the bottom shows an X 3.4 class fare observed by the Hinode 1 Parker Solar Probe Meeting, Laurel, USA satellite in a complex active region on 13 December 2006. Hinode recorded March 31- April 1: the fare through a Ca II H flter, which samples the solar chromosphere. The SOLARNET Public Engagement Training Workshop, extreme brightening is due to energy released by the reconnection of mag- Northumbria University, UK netic feld lines. MARCH MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 28 29 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Solar spectroscopy Top: John Evershed (1918). Bottom: Hinode’s Spectro-Polarimeter (2006) Photograph of the solar intensity spectrum taken by John Ever- shed at Kodaikanal Observatory (India) on 20 November 1918. The vertical dark lines are spectral absorption lines created by the diferent chemical ele- ments present in the solar atmosphere. The horizontal dark band is a sun- spot. Spectral lines are slightly tilted at the position of the sunspot, due to March 31 - April 1: the existence of horizontal gas motions in the sunspot penumbra – known SOLARNET Public Engagement Training Workshop, as Evershed fows. Northumbria University, UK The lower panel shows modern spectroscopic measurements by the spec- April 22: tropolarimeter aboard the Hinode satellite. The data were taken on 13 De- Peak of Lyrids meteor shower (07:00 GMT) cember 2006 at the position of a faring sunspot. The spectrum on the right April 23: displays the four polarization states of the light in two iron lines at 630 nm. Peak of Pi Puppids meteor shower (12:00 GMT) The spectral resolution of these observations is much higher than that of the spectrum taken by Evershed. APRIL MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 30 31 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Active region prominences Top: Lorenzo Respighi (1870). Bottom: Hinode’s Broadband Filter Imager (2007) Prominences observed by Lorenzo Respighi in 1870 at the border of the solar disk near the position of active regions (top). These detailed draw- ings show the wide range of shapes and sizes of active region prominences. The observations were made using spectroscopic techniques, which were very advanced in Italy at that time. Active region prominences are smaller, May 3-8: shorter, and more dynamical than quiescent prominences occurring far from EGU General Assembly, Vienna, Austria sunspots. May 5: The lower image shows an active region prominence observed by the Hinode Peak of Eta Aquariids meteor shower (21:00 GMT) satellite on January 12, 2007. The measurements were taken in the H line of ionized calcium. The prominence exhibits delicate threads that are believed to trace the chromospheric magnetic feld. It shows a very rapid evolution, changing shape constantly. The sunspot associated with the prominence can be seen as a dark feature near the right border of the image. MAY MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 29 30 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Solar prominences Angelo Secchi (1872) Prominences observed by Father Angelo Secchi in July 1872 at the border of the solar disk. The measurements were made using spectro- scopic techniques, which allowed astronomers to see the prominences out of total solar eclipses. Indeed, spectroscopy made it possible to monitor the solar limb daily in search for prominences and other solar phenomena. Their June 14-19: number was found to vary in phase with the solar cycle. Prominences were SPIE Astronomical Telescopes, Yokohama, Japan thought to be eruptions of the chromosphere, coming in diferent shapes and sizes. Secchi proposed a complex classifcation consisting of several June 20: groups. Summer Solstice (21:43 GMT) June 21: Due to their strong emission in chromospheric lines, notably the H-alpha line, Annular solar eclipse prominences were soon considered to be made of hot gas. This view stands today, although we also know that prominences are much cooler than the June 22-26: coronal plasma where they are embedded. Cool Stars 21, Toulouse, France JUNE MON TUE WED THU FRI SAT SUN MON TUE WED THU FRI SAT SUN 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 01 02 The European Solar Telescope (EST) is the next step in the European quest for a better understanding of the Sun Solar filaments Top: Observatoire de Meudon (1909). Bottom: ChroTel (2011) The photograph on top is one the frst H-alpha spectroheliograms re- corded at Observatoire de Meudon (Paris, France). Taken on 15 June 1909, it shows the chromosphere of the Sun. The dark long structures visible on the solar disk are flaments. When observed at the limb, flaments are called prominences and appear bright. July 5: Penumbral lunar eclipse The CCD image at the bottom shows the solar chromosphere in H-alpha as recorded by the Chromospheric Telescope (ChroTel) on 15 November 2011.
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